Today, the refinery still processes a combination of sour and sweet crudes. Brorman estimated the refinery processes about 80 percent sour and 20 percent sweet crude. About 85 percent of those crudes are turned into gasoline, diesel and jet fuel.

That combination fluctuates, depending on the price differential between West Texas sweet and West Texas sour, he said.

“The reason we ran more sour than sweet is the discount. Sour could be $4, $5, $6 less than sweet. But in the last couple of years, WTI has at times actually gotten cheaper,” he said.

“We’re trying to push to run more WTI because the differential is low. If we could buy WTI for the same price, we would prefer it because it makes more gasoline than West Texas sour. There are more advantages, from a pricing and product standpoint to use intermediate than sour,” he said.

The percentage could shift 1 or 2 percent but could mean as much as $2 more per barrel because the sweeter crude yields more gasoline and less asphalt. “That’s where we get our value,” he said.

West Texas Sour has started to increase in price because of the additional pipeline capacity that has been added in recent years, he said. Producers are shipping more sour crude to refineries that are set up to process the heavier crude.

It’s that price differential and the impact on the company’s margins that influence the decision on which class of crude to buy, not the price of oil, Brorman said.

“We’re buying crude at whatever the price is, making product and turning and selling that product at whatever the market price is. We’re always looking at the margins between the crude price and the product price.”

Cheaper crude does not necessarily translate into higher margins because product prices tend to fall, as well, he said.

Like other refineries, the Big Spring plant is limited in the amount of light crude it can run, Brorman said.

“For most of my career here, going back to the 1990s, refineries have invested heavily in processing the heavier crudes,” he said. Expectations were the nation’s refineries would have to be dependent on heavier, more sour crudes coming from overseas. Instead, technology has helped U.S. operators find new reserves of lighter, sweeter crudes.

Lately, refineries have invested money in equipment to handle the lighter sweet crudes coming from shale plays in the Permian Basin, the Eagle Ford and Bakken, he said. “They’re not investing enough” to handle the rise in production, he said.

The refinery’s output has rebounded from 40,000 barrels a day to about 73,000 barrels a day today as the plant has expanded in incremental steps, Brorman said. Employment is up to about 200, with only a handful of open positions.

With the downturn in the industry, the refinery is seeing more applicants and a higher quality of applicants, he said.

Current investment plans include some environmental projects in preparation for new federal regulations, as well as some equipment repair and other small projects to boost margins, Brorman reported.

Asked about the debate between producers and refiners over whether or not to lift the 40-year-old ban on exporting crude, he said that, overall, “We’d be against it, mainly because we’re not producers.”

Producers feel lifting the ban would let them sell their oil to overseas refiners who can process more of the lighter crude. “They think that would bring more value,” Brorman said.